This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are investigating the structure of the U2-U6 snRNA complex from S. cerevisiae. This large RNA complex has been highly conserved throughout eukaryotic evolution, and forms the catalytic core of the spliceosome. The RNA structure will be investigated at a range of temperatures, pH and ionic conditions. NMR experiments that we will need to collect include: 1D (1H), 2D NOESY, 2D 1H-15N HSQC (normal and TROSY enhanced), 2D 1H-15N HNN COSY, 2D 1H-13C HSQC (normal and TROSY enhanced), 2D NOESY, 2D 1H,13C filter/edit NOESY. Residual dipolar couplings will be measured for samples in both isotropic and partially aligned states (via addition of Pf1 phage).